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Species

Introduction

Species is a type that stores information about a particle.

A Species stores the following information:

  • name: name of the particle to track
  • charge: charge of the particle
  • mass: mass of the particle
  • spin: spin of the particle
  • moment: magnetic moment of the particle
  • iso: mass number of atomic isotope
  • kind: The kind field classifies species into five types: ATOM, HADRON, LEPTON, PHOTON, and NULL.

Note: The NULL kind serves as a placeholder that can be used by Julia code. For example, if a struct has a Species component, a NULL species can be used as an initial value to indicate that the species component has not yet been set.

Getter Functions

To access mass or charge of a species, use massof() getter function for mass, and chargeof() getter function for charge. The function will return unit given to @APCdef. See this page for more information.

Use the function nameof() to access the species name.

kindof() returns the kind of the Species.

Construct a Species

Use the constructor Species(::String) to create a species.

Note: Species names follow the OpenPMD standard.

Constructing a Null Species

The Null species is useful for bookkeeping purposes, such as a placeholder in a struct component to indicate an unset species. To instantiate:

julia> Species("Null")
julia> Species() # Same as above

Constructing Subatomic Species

To construct a subatomic species, provide the exact name of the particle in the name field. Note that the name must be provided exactly.

Example:

julia> Species("electron")

For antiparticles, prepend "anti-" to the name.

Example:

julia> Species("anti-proton")

See the list of all available subatomic species at the end of this page.

Constructing Atomic Species

To construct an atomic species, include these components in name:

  • Atomic Symbol
  • Mass number of the atom (optional), format:
    • Mass number before the atomic symbol (accepts unicode superscript)
    • Optional "#" symbol at the beginning
    • If not specified, uses the average of the mass in naturally occurring samples.
  • These formats all represent Hydrogen-1:
julia> Species("1H")
julia> Species("¹H")
julia> Species("#1H")
  • Charge (optional), format (all accept unicode superscript):
    • "+" for single positive charge
    • "++" for double positive charge
    • "+n" or "n+" for n positive charges
    • "-" for single negative charge
    • "--" for double negative charge
    • "-n" or "n-" for n negative charges
    • Defaults to 0 if not specified
  • Add "anti-" prefix to construct an anti-atom

Example:

julia> Species("13C+")   # Carbon-13 with a single positive charge
julia> Species("¹⁵N³⁻")  # Nitrogen-15 with a 3 negative charge
julia> Species("Al+3")   # Average Aluminum with 3 positive charge
julia> Species("anti-H") # Anti-hydrogen

List of Available Subatomic Species

  • anti-deuteron
  • anti-electron or positron
  • anti-neutron
  • anti-proton
  • anti-muon
  • deuteron
  • electron
  • muon
  • neutron
  • photon
  • pion0
  • pion+
  • pion-
  • positron
  • proton